1. Field
The present invention relates to a muffler for a small-sized vehicle, in which the muffler is connected to an exhaust system of an engine of a small-sized vehicle such as a motorcycle, a catalyst is contained in the muffler, and a reduction in exhaust resistance and a decrease in exhaust noise are achieved at the same time.
2. Description of Related Art
A conventional muffler has been known in which the inside of a cylinder-shaped case of the muffler is divided into multiple expansion chambers by partition walls, and a catalyst is contained in a particular one of the expansion chambers (see Patent Document 1, Japanese Patent Application Publication No. 2005-240720).
In such a muffler, by enlarging the volume of the expansion chamber containing the catalyst this expansion chamber is expected to make the exhaust pressure lower at the downstream of the catalyst, to reduce the exhaust resistance, to make the flow of the exhaust gas better, to enhance the engine performance, and in addition, to reduce the exhaust noise. However, the enlargement of the volume of the expansion chamber containing the catalyst poses a problem that an outer plate of the muffler, which surrounds the expansion chamber, vibrates due to its reception of the noise of the exhaust gas and noise of reaction of the catalyst, and accordingly causes noise.